Insulating boot for electrosurgical forceps

ABSTRACT

Either an endoscopic or open bipolar forceps includes a flexible, generally tubular insulating boot for insulating patient tissue, while not impeding motion of the jaw members. The jaw members are movable from an open to a closed position and the jaw members are connected to a source of electrosurgical energy such that the jaw members are capable of conducting energy through tissue held therebetween to effect a tissue seal. A knife assembly may be included that allows a user to selectively divide tissue upon actuation thereof. The insulating boot may be made from a viscoelastic, elastomeric or flexible material suitable for use with a sterilization process including ethylene oxide.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalPatent Application Ser. No. 60/722,213 by Scott DePierro et al.,entitled “INSULATING BOOT FOR ELECTROSURGICAL FORCEPS” filed on Sep. 30,2005, now U.S. patent application Ser. No. 11/529,798 published as U.S.Patent Application Publication No. US2007/0078458 A1, the entirecontents of which is incorporated by reference herein. This applicationcross-references U.S. Provisional Patent Application Ser. No. 60/722,186by Paul Guerra, entitled “METHOD FOR MANUFACTURING AN END EFFECTORASSEMBLY,” filed on Sep. 30, 2005, now U.S. patent application Ser. No.11/529,414 published as U.S. Patent Application Publication No.US2007/0074807 A1 and U.S. Provisional Patent Application Ser. No.60/722,359 by Kristin Johnson et al, entitled “FLEXIBLE ENDOSCOPICCATHETER WITH LIGASURE,” [[both]] filed on Sep. 30, 2005, now U.S.patent application Ser. No. 11/540,779 published as U.S. PatentApplication Publication No. US2007/0078559A1, the entire contents ofboth applications being incorporated by reference herein.

BACKGROUND

1. Technical Field

The present disclosure relates to an insulated electrosurgical forcepsand more particularly, the present disclosure relates to an insulatingboot for use with either an endoscopic or open bipolar and/or monopolarelectrosurgical forceps for sealing, cutting, and/or coagulating tissue.

2. Background of Related Art

Electrosurgical forceps utilize both mechanical clamping action andelectrical energy to effect hemostasis by heating the tissue and bloodvessels to coagulate, cauterize and/or seal tissue. As an alternative toopen forceps for use with open surgical procedures, many modern surgeonsuse endoscopes and endoscopic instruments for remotely accessing organsthrough smaller, puncture-like incisions. As a direct result thereof,patients tend to benefit from less scarring and reduced healing time.

Endoscopic instruments are inserted into the patient through a cannula,or port, which has been made with a trocar. Typical sizes for cannulasrange from three millimeters to twelve millimeters. Smaller cannulas areusually preferred, which, as can be appreciated, ultimately presents adesign challenge to instrument manufacturers who must find ways to makeendoscopic instruments that fit through the smaller cannulas.

Many endoscopic surgical procedures require cutting or ligating bloodvessels or vascular tissue. Due to the inherent spatial considerationsof the surgical cavity, surgeons often have difficulty suturing vesselsor performing other traditional methods of controlling bleeding, e.g.,clamping and/or tying-off transected blood vessels. By utilizing anendoscopic electrosurgical forceps, a surgeon can either cauterize,coagulate/desiccate and/or simply reduce or slow bleeding simply bycontrolling the intensity, frequency and duration of the electrosurgicalenergy applied through the jaw members to the tissue. Most small bloodvessels, i.e., in the range below two millimeters in diameter, can oftenbe closed using standard electrosurgical instruments and techniques.However, if a larger vessel is ligated, it may be necessary for thesurgeon to convert the endoscopic procedure into an open-surgicalprocedure and thereby abandon the benefits of endoscopic surgery.Alternatively, the surgeon can seal the larger vessel or tissue.

It is thought that the process of coagulating vessels is fundamentallydifferent than electrosurgical vessel sealing. For the purposes herein,“coagulation” is defined as a process of desiccating tissue wherein thetissue cells are ruptured and dried. “Vessel sealing” or “tissuesealing” is defined as the process of liquefying the collagen in thetissue so that it reforms into a fused mass. Coagulation of smallvessels is sufficient to permanently close them, while larger vesselsneed to be sealed to assure permanent closure.

In order to effectively seal larger vessels (or tissue) two predominantmechanical parameters must be accurately controlled—the pressure appliedto the vessel (tissue) and the gap distance between the electrodes—bothof which are affected by the thickness of the sealed vessel. Moreparticularly, accurate application of pressure is important to opposethe walls of the vessel; to reduce the tissue impedance to a low enoughvalue that allows enough electrosurgical energy through the tissue; toovercome the forces of expansion during tissue heating; and tocontribute to the end tissue thickness which is an indication of a goodseal. It has been determined that a typical fused vessel wall is optimumbetween 0.001 and 0.006 inches (about 0.03 mm to about 0.15 mm). Belowthis range, the seal may shred or tear and above this range the lumensmay not be properly or effectively sealed.

With respect to smaller vessels, the pressure applied to the tissuetends to become less relevant whereas the gap distance between theelectrically conductive surfaces becomes more significant for effectivesealing. In other words, the chances of the two electrically conductivesurfaces touching during activation increases as vessels become smaller.

Many known instruments include blade members or shearing members whichsimply cut tissue in a mechanical and/or electromechanical manner andare relatively ineffective for vessel sealing purposes. Otherinstruments rely on clamping pressure alone to procure proper sealingthickness and are not designed to take into account gap tolerancesand/or parallelism and flatness requirements which are parameters which,if properly controlled, can assure a consistent and effective tissueseal. For example, it is known that it is difficult to adequatelycontrol thickness of the resulting sealed tissue by controlling clampingpressure alone for either of two reasons: 1) if too much force isapplied, there is a possibility that the two poles will touch and energywill not be transferred through the tissue resulting in an ineffectiveseal; or 2) if too low a force is applied the tissue may pre-maturelymove prior to activation and sealing and/or a thicker, less reliableseal may be created.

As mentioned above, in order to properly and effectively seal largervessels or tissue, a greater closure force between opposing jaw membersis required. It is known that a large closure force between the jawstypically requires a large moment about the pivot for each jaw. Thispresents a design challenge because the jaw members are typicallyaffixed with pins which are positioned to have small moment arms withrespect to the pivot of each jaw member. A large force, coupled with asmall moment arm, is undesirable because the large forces may shear thepins. As a result, designers must compensate for these large closureforces by either designing instruments with metal pins and/or bydesigning instruments which at least partially offload these closureforces to reduce the chances of mechanical failure. As can beappreciated, if metal pivot pins are employed, the metal pins must beinsulated to avoid the pin acting as an alternate current path betweenthe jaw members which may prove detrimental to effective sealing.

Increasing the closure forces between electrodes may have otherundesirable effects, e.g., it may cause the opposing electrodes to comeinto close contact with one another which may result in a short circuitand a small closure force may cause pre-mature movement of the tissueduring compression and prior to activation. As a result thereof,providing an instrument which consistently provides the appropriateclosure force between opposing electrode within a preferred pressurerange will enhance the chances of a successful seal. As can beappreciated, relying on a surgeon to manually provide the appropriateclosure force within the appropriate range on a consistent basis wouldbe difficult and the resultant effectiveness and quality of the seal mayvary. Moreover, the overall success of creating an effective tissue sealis greatly reliant upon the user's expertise, vision, dexterity, andexperience in judging the appropriate closure force to uniformly,consistently and effectively seal the vessel. In other words, thesuccess of the seal would greatly depend upon the ultimate skill of thesurgeon rather than the efficiency of the instrument.

It has been found that the pressure range for assuring a consistent andeffective seal is between about 3 kg/cm² to about 16 kg/cm² and,preferably, within a working range of 7 kg/cm² to 13 kg/cm².Manufacturing an instrument which is capable of providing a closurepressure within this working range has been shown to be effective forsealing arteries, tissues and other vascular bundles.

Various force-actuating assemblies have been developed in the past forproviding the appropriate closure forces to effect vessel sealing. Forexample, one such actuating assembly has been developed by ValleylabInc., a division of Tyco Healthcare LP, for use with Valleylab's vesselsealing and dividing instrument commonly sold under the trademarkLIGASURE ATLAS®. This assembly includes a four-bar mechanical linkage, aspring and a drive assembly which cooperate to consistently provide andmaintain tissue pressures within the above working ranges. The LIGASUREATLAS® is presently designed to fit through a 10 mm cannula and includesa bi-lateral jaw closure mechanism which is activated by a foot switch.A trigger assembly extends a knife distally to separate the tissue alongthe tissue seal. A rotating mechanism is associated with distal end ofthe handle to allow a surgeon to selectively rotate the jaw members tofacilitate grasping tissue. U.S. Pat. Nos. 7,101,371 and 7,083,618 andPCT Application Ser. Nos. PCT/US01/01890 PCT/US02/01890, now WO2002/080799, and PCT/US01/11340, now WO 2002/080795, describe in detailthe operating features of the LIGASURE ATLAS® and various methodsrelating thereto. Co-pending U.S. application Ser. No. 10/970,307, nowU.S. Pat. No. 7,232,440, relates to another version of an endoscopicforceps sold under the trademark LIGASURE V® by Valleylab, Inc., adivision of Tyco Healthcare, LP. In addition, commonly owned, U.S.patent application Ser. No. 10/873,860, filed on Jun. 22, 2004 andentitled “Open Vessel Sealing Instrument with Cutting Mechanism andDistal Lockout”, now U.S. Pat. No. 7,252,667, and incorporated byreference in its entirety herein discloses an open forceps which isconfigured to seal and cut tissue which can be configured to include oneor more of the presently disclosed embodiments described herein. Theentire contents of all of these applications are hereby incorporated byreference herein.

For example, the commonly owned U.S. patent application Ser. No.10/970,307 filed on Oct. 21, 2004 and entitled “Bipolar Forceps HavingMonopolar Extension”, now U.S. Pat. No. 7,232,440, discloses anelectrosurgical forceps for coagulating, sealing, and/or cutting tissuehaving a selectively energizable and/or extendable monopolar extensionfor enhanced electrosurgical effect. The instrument includes a monopolarelement which may be selectively extended and selectively activated totreat tissue. Various different designs are envisioned which allow auser to selectively energize tissue in a bipolar or monopolar mode toseal or coagulate tissue depending upon a particular purpose. Some ofthe various designs include: (1) a selectively extendable andenergizable knife design which acts as a monopolar element; (2) a bottomjaw which is electrically and selectively configured to act as amonopolar element; (3) tapered jaw members having distal ends which areselectively energized with a single electrical potential to treat tissuein a monopolar fashion; and (4) other configurations of the end effectorassembly and/or bottom or second jaw member which are configured to suita particular purpose or to achieve a desired surgical result.

However, a general issue with existing electrosurgical forceps is thatthe jaw members rotate about a common pivot at the distal end of a metalor otherwise conductive shaft such that there is potential for both thejaws, a portion of the shaft, and the related mechanism components toconduct electrosurgical energy (either monopolar or as part of a bipolarpath) to the patient tissue. Existing electrosurgical instruments withjaws either cover the pivot elements with an inflexible shrink-tube ordo not cover the pivot elements and connection areas and leave theseportions exposed.

SUMMARY

It would be desirous to provide electrosurgical instruments with aflexible insulating boot that both permits pivoting and other associatedmovements of the jaw members and also reduces the potential for stray ormiscellaneous currents affecting surrounding tissue.

The present disclosure relates to an electrosurgical forceps having ashaft with jaw members at a distal end thereof. The jaw members aremovable about a pivot by actuation of a drive assembly that moves thejaw members from a first position wherein the jaw members are disposedin spaced relation relative to one another to a second position whereinthe jaw members are closer to one another for grasping and treatingtissue. The forceps also includes a movable handle that actuates thedrive assembly to move the jaw members relative to one another.

At least one jaw member is adapted to connect to a source of electricalenergy such that at least one of the jaw members is capable ofconducting energy to tissue held therebetween to treat tissue. Aflexible insulating boot is disposed on at least a portion of anexterior surface of at least one jaw member. The insulating boot isconfigured and made from a material that insulates tissue from variousexposed areas of the shaft and the jaw members.

In one particularly useful embodiment, one end of the insulating boot isdisposed on at least a portion of an exterior surface of the shaft andanother end of the insulating boot is disposed on at least a portion ofan exterior surface of at least one jaw member proximate the pivot suchthat movement of the jaw members is substantially unimpeded. In anotherembodiment according to the present disclosure, the insulating boot ismade of at least one of a viscoelastic, elastomeric, and flexiblematerial suitable for use with a sterilization process that does notsubstantially impair structural integrity of the boot. In particular,the sterilization process may include ethylene oxide.

The jaw members (or jaw member) may also include a series of stopmembers disposed thereon for regulating distance between the jaw memberssuch that a gap is created between the jaw members during the sealingprocess.

The forceps may also include a knife that is selectively deployable tocut tissue disposed between the jaw members.

In one embodiment, the jaw members are configured to treat tissue in amonopolar fashion, while in another embodiment, the jaw members areconfigured to treat tissue in a bipolar fashion.

In one embodiment of the present disclosure, the present disclosure isdirected to an electrosurgical forceps for sealing tissue having a pairof first and second shaft members each with a jaw member disposed at adistal end thereof. The jaw members are movable about a pivot from afirst position in spaced relation relative to one another to at leastone subsequent position wherein the jaw members cooperate to grasptissue therebetween. At least one of the jaw members includes anelectrically conductive sealing plate adapted to communicateelectrosurgical energy to tissue held therebetween and a flexibleinsulating boot disposed on at least a portion of an exterior surface ofat least one jaw member.

In yet another useful embodiment, the present disclosure relates to anelectrosurgical forceps having a housing with a shaft affixed thereto.The shaft includes first and second jaw members attached to a distal endthereof. The forceps includes an actuator for moving jaw membersrelative to one another from a first position wherein the jaw membersare disposed in spaced relation relative to one another to a secondposition wherein the jaw members cooperate to grasp tissue therebetween.Each jaw member is adapted to connect to a source of electrosurgicalenergy such that the jaw members are selectively capable of conductingenergy to tissue held therebetween to treat tissue.

The forceps also includes a knife that is selectively moveable within aknife channel defined within at least one of the jaw members to cuttissue disposed therebetween. A monopolar element is housed within atleast one jaw member and is selectively movable from a first proximalposition within the jaw members to a second distal position within thejaw member(s). The monopolar element may be connected to the source ofelectrosurgical energy and may be selectively activatable independentlyof the jaw members. The forceps includes a flexible insulating bootdisposed on at least a portion of at least one jaw member.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the subject instrument are described herein withreference to the drawings wherein:

FIG. 1 is a left, perspective view of one version of the presentdisclosure that includes an endoscopic bipolar forceps showing ahousing, a shaft and an end effector assembly having an insulating bootaccording to the present disclosure;

FIG. 2 is an enlarged, left perspective view of the end effectorassembly with the jaw members shown in open configuration having theinsulating boot according to the present disclosure;

FIG. 3 is a full perspective view of the end effector assembly of FIG. 1having the insulating boot according to the present disclosure;

FIG. 4 is an exploded top, perspective view of the housing and internalworking components thereof of the endoscopic bipolar forceps of FIG. 1with parts separated;

FIG. 5 is an enlarged, top, perspective view of the end effectorassembly having the insulating boot of the present disclosure with partsseparated;

FIG. 6 is an enlarged, perspective view of the knife assembly with partsseparated;

FIG. 7 is an enlarged view of the indicated area of detail of FIG. 6showing a knife blade of the knife assembly;

FIG. 8 is a greatly-enlarged, perspective view of a distal end of theknife assembly;

FIG. 9 is a greatly-enlarged, perspective view of a knife drive of theknife assembly;

FIG. 10 is a cross-section of the housing with the end effector shown inopen configuration having the insulating boot of the present disclosureand showing the internal, electrical routing of an electrosurgical cableand electrical leads;

FIG. 11 is a greatly-enlarged view of the indicated area of detail ofFIG. 10;

FIG. 12 is a side, cross section of the shaft and end effector assemblywith the end effector assembly having the insulating boot of the presentdisclosure;

FIG. 13 is a side, cross section of the housing showing the movingcomponents of the drive assembly during actuation and the end effectorassembly;

FIG. 14 is a greatly-enlarged view of the indicated area of detail inFIG. 13;

FIG. 15 is a greatly-enlarged view of the indicated area of detail inFIG. 13;

FIG. 16 is an enlarged, side view of the end effector assembly shown inan open configuration and having the insulating boot of the presentdisclosure;

FIG. 17 is a side view of the end effector assembly shown in a closedconfiguration and having the insulating boot of the present disclosurewith the jaw members in the closed position;

FIG. 18 is an enlarged, rear, perspective view of the end effectorsshown grasping tissue;

FIG. 19 is a side, cross section of a tissue seal after separation bythe knife assembly;

FIG. 20 is a left, front perspective view of an open forceps with acutting mechanism having an insulating boot according to the presentdisclosure;

FIG. 21 is a right, rear perspective view of the forceps of FIG. 20;

FIG. 22 is an enlarged, left perspective view of one of the jaw membersof the forceps of FIG. 20;

FIG. 23 is an enlarged, perspective view of the other jaw member of theforceps of FIG. 20;

FIG. 24 is a side cross sectional view showing the forceps of FIG. 20 inopen configuration for grasping tissue;

FIG. 25 is a rear, perspective view of the forceps of FIG. 20 showngrasping tissue with a ratchet mechanism shown prior to engagement;

FIG. 26 is a side view of an endoscopic forceps showing a housing, ashaft, an end effector assembly having an insulating boot according tothe present disclosure and a trigger assembly in a first position;

FIG. 27 is an enlarged, cross section taken along line 27-27 of FIG. 26;

FIG. 28 is an enlarged, side view of the trigger assembly of FIG. 26;

FIG. 29 is an enlarged, side view of the embodiment of an end effectorassembly of FIG. 26 having the insulating boot according to the presentdisclosure and showing relative extension of a monopolar element from adistal end of the end effector assembly;

FIG. 30 is a side view of the trigger assembly in a second position foradvancing a knife within the end effector assembly and having theinsulating boot according to the present disclosure;

FIG. 31 is a side view of the trigger assembly in a third position forextending a monopolar element from a distal end of the end effectorassembly;

FIG. 32 is a side view of an alternate embodiment of the presentinvention showing a second actuator advancing the monopolar elementrelative to the distal end of the end effector;

FIG. 33A is an enlarged, side schematic view of one embodiment of an endeffector assembly having the insulating boot according to the presentdisclosure and showing relative movement of a first jaw member relativeto a second jaw member prior to advancement of the knife through the endeffector assembly;

FIG. 33B is an enlarged, side schematic view of the end effectorassembly showing relative movement of the knife through the end effectorassembly to divide tissue;

FIG. 33C is an enlarged, side schematic view of the end effectorassembly showing relative movement of the knife extending from thedistal end of the end effector assembly;

FIG. 34A is an enlarged, side schematic view of another embodiment of anend effector assembly having the insulating boot according to thepresent disclosure;

FIG. 34B is schematic view of another embodiment of an end effectorassembly capable of being configured with the insulating boot accordingto the present disclosure and showing a series of electrical connectionsto a control switch and a generator to enable both bipolar activationand monopolar activation;

FIG. 34C is a table showing the various modes of operation of theforceps utilizing the end effector configuration of FIG. 34B;

FIGS. 35A and 35B are enlarged views of an alternate embodiment of thesecond jaw member configured with an insulating boot according to thepresent disclosure;

FIGS. 36A and 36B are enlarged views of another alternate embodiment ofthe second jaw member configured with an insulating boot according tothe present disclosure;

FIGS. 37A and 37B are enlarged views of another alternate embodiment ofthe end effector assembly configured with an insulating boot accordingto the present disclosure showing the monopolar element in an extendedconfiguration; and

FIGS. 38A and 38B are enlarged views of yet another alternate embodimentof the second jaw member configured with an insulating boot according tothe present disclosure.

DETAILED DESCRIPTION

Referring initially to FIGS. 1-3, one particularly useful endoscopicforceps 10 is shown for use with various surgical procedures andgenerally includes a housing 20, a handle assembly 30, a rotatingassembly 80, a trigger assembly 70, a knife assembly and an end effectorassembly 100 that mutually cooperate to grasp, seal and divide tubularvessels and vascular tissue 420 (see FIGS. 18-19). For the purposesherein, forceps 10 will be described generally. However, the variousparticular aspects of this particular forceps are detailed in commonlyowned U.S. patent application Ser. No. 10/460,926, filed on Jun. 13,2003, and entitled “VESSEL SEALER AND DIVIDER FOR USE WITH SMALL TROCARSAND CANNULAS,” now U.S. Pat. No. 7,156,846, and previously mentionedU.S. patent application Ser. No. 10/970,307, now U.S. Pat. No.7,232,440, the entire contents of each of which are incorporated byreference herein. Forceps 10 includes a shaft 12 that has a distal end16 dimensioned to mechanically engage the end effector assembly 100 anda proximal end 14 that mechanically engages the housing 20. As will bediscussed in more detail below, the end effector assembly 100 includes aflexible insulating boot 500 configured to cover at least a portion ofthe exterior surfaces of the end effector assembly 100.

Forceps 10 also includes an electrosurgical cable 310 that connects theforceps 10 to a source of electrosurgical energy, e.g., a generator (notshown). The generator includes various safety and performance featuresincluding isolated output, independent activation of accessories, andInstant Response™ technology (a proprietary technology of Valleylab,Inc., a division of Tyco Healthcare, LP) that provides an advancedfeedback system to sense changes in tissue many times per second andadjust voltage and current to maintain appropriate power. Cable 310 isinternally divided into cable lead 310 a, 310 b and 310 c that eachtransmit electrosurgical energy through their respective feed pathsthrough the forceps 10 to the end effector assembly 100. (See FIG. 11).

Handle assembly 30 includes a fixed handle 50 and a movable handle 40.Fixed handle 50 is integrally associated with housing 20 and handle 40is movable relative to fixed handle 50. Rotating assembly 80 isintegrally associated with the housing 20 and is rotatable approximately180 degrees in either direction about a longitudinal axis “A” (See FIG.1). Details of the rotating assembly 80 are described in more detailbelow.

As best seen in FIGS. 1 and 4, housing 20 is formed from two (2) housinghalves 20 a and 20 b that each include a plurality of interfaces 27 a-27f that are dimensioned to mechanically align and engage one another toform housing 20 and enclose the internal working components of forceps10. Fixed handle 50 that, as mentioned above, is integrally associatedwith housing 20, takes shape upon the assembly of the housing halves 20a and 20 b. Movable handle 40 and trigger assembly 70 are of unitaryconstruction and are operatively connected to the housing 20 and thefixed handle 50 during the assembly process. Rotating assembly 80includes two halves that, when assembled, form a knurled wheel 82 that,in turn, houses a drive assembly 150 and a knife assembly 140.

As mentioned above, end effector assembly 100 is attached at the distalend 14 of shaft 12 and includes a pair of opposing jaw members 110 and120. Movable handle 40 of handle assembly 30 is ultimately connected tothe drive assembly 150 that, together, mechanically cooperate to impartmovement of the jaw members 110 and 120 from an open position whereinthe jaw members 110 and 120 are disposed in spaced relation relative toone another, to a clamping or closed position wherein the jaw members110 and 120 cooperate to grasp tissue therebetween. All of thesecomponents and features are best explained in detail in theabove-identified commonly owned U.S. application Ser. No. 10/460,926,now U.S. Pat. No. 7,156,846.

Turning now to the more detailed features of the present disclosure asdescribed with respect to FIGS. 1-4, movable handle 40 includes a fingerloop 41 that has an aperture 42 defined therethrough that enables a userto grasp and move the handle 40 relative to the fixed handle 50. As bestseen in FIG. 4, movable handle 40 is selectively moveable about a pairof pivot pins 29 a and 29 b from a first position relative to fixedhandle 50 to a second position in closer proximity to the fixed handle50 that, as explained below, imparts movement of the jaw members 110 and120 relative to one another. The movable handle include a clevis 45 thatforms a pair of upper flanges 45 a and 45 b each having an aperture 49 aand 49 b, respectively, at an upper end thereof for receiving the pivotpins 29 a and 29 b therethrough and mounting the upper end of the handle40 to the housing 20. In turn, each pin 29 a and 29 b mounts to arespective housing half 20 a and 20 b.

Each upper flange 45 a and 45 b also includes a force-actuating flangeor drive flange 47 a and 47 b, respectively, each of which is alignedalong longitudinal axis “A” and which abut the drive assembly 150 suchthat pivotal movement of the handle 40 forces actuating flange againstthe drive assembly 150 that, in turn, closes the jaw members 110 and120.

Movable handle 40 is designed to provide a distinct mechanical advantageover conventional handle assemblies due to the unique position of thepivot pins 29 a and 29 b (i.e., pivot point) relative to thelongitudinal axis “A” of the shaft 12 and the disposition of the drivingflange 47 along longitudinal axis “A”. In other words, by positioningthe pivot pins 29 a and 29 b above the driving flange 47, the user gainslever-like mechanical advantage to actuate the jaw members 110 and 120enabling the user to close the jaw members 110 and 120 with lesser forcewhile still generating the required forces necessary to effect a properand effective tissue seal.

In addition, the unilateral closure design of the end effector assembly100 will also increase mechanical advantage. More particularly, as bestshown in FIGS. 3 and 5, the unilateral end effector assembly 100includes one stationary or fixed jaw member 120 that is mounted in fixedrelation to the shaft 12 and a pivoting jaw member 110 mounted about apivot pin 103 attached to the stationary jaw member 120. A reciprocatingsleeve 60 is slidingly disposed within the shaft 12 and is remotelyoperable by the drive assembly 150 to move jaw member 110 relative tojaw member 120. The pivoting jaw member 110 includes a detent orprotrusion 117 that extends from jaw member 110 through an aperture 62disposed within the reciprocating sleeve 60 (FIG. 3). The pivoting jawmember 110 is actuated by sliding the sleeve 60 axially within the shaft12 such that a distal end 63 of the aperture 62 abuts against the detent117 on the pivoting jaw member 110 (See FIG. 3). Pulling the sleeve 60proximally closes the jaw members 110 and 120 about tissue graspedtherebetween and pushing the sleeve 60 distally opens the jaw members110 and 120 for grasping purposes.

As best illustrated in FIGS. 3-9 and 18, a knife channel 115 a and 115 bruns through the center of the jaw members 110 and 120, respectively,such that a blade 185 from the knife assembly 140 can cut the tissue 420grasped between the jaw members 110 and 120 when the jaw members 110 and120 are in a closed position. More particularly, the blade 185 can onlybe advanced through the tissue 420 when the jaw members 110 and 120 areclosed, thus preventing accidental or premature activation of the blade185 through the tissue 420. The unilateral end effector assembly 100 isstructured such that electrical energy can be routed through the sleeve60 at the protrusion 117 contact point with the sleeve 60 or using a“brush” or lever (not shown) to contact the back of the moving jawmember 110 when the jaw member 110 closes. In this instance, theelectrical energy would be routed through the protrusion 117 to thestationary jaw member 120.

As best illustrated in FIG. 2, jaw member 110 also includes a jawhousing 116 that has an insulative substrate or insulator 114 and anelectrically conductive surface 112. Details relating to the specificstructure of the jaw members 110 and 120 are disclosed in previouslymentioned commonly owned U.S. patent application Ser. No. 10/460,926.

As best shown in FIGS. 3 and 16, jaw member 110 includes a pivot flange118 that, in turn, includes protrusion 117 that extends from pivotflange 118 and has an arcuately-shaped inner surface 111 dimensioned tomatingly engage the aperture 62 of sleeve 60 upon retraction thereof.Pivot flange 118 also includes a pin slot 119 that is dimensioned toengage pivot pin 103 to allow jaw member 110 to rotate relative to jawmember 120 upon retraction of the reciprocating sleeve 60. As explainedin more detail below, pivot pin 103 mounts to the stationary jaw member120 through a pair of apertures 101 a and 101 b disposed within aproximal portion of the jaw member 120. The pivot pin 103 serves as acommon joint between the jaw members 110 and 120.

Jaw member 120 is designed to be fixed to the end of a rotating tube 160that is part of the rotating assembly 80 such that rotation of the tube160 around axis “B” of FIG. 1 will impart rotation to the end effectorassembly 100 (See FIGS. 1, 2 and 15). Details relating to the rotationof the jaw members 110 and 120 are described in the previously mentionedcommonly owned U.S. patent application Ser. No. 10/460,926, now U.S.Pat. No. 7,156,846, that is incorporated by reference herein in itsentirety.

Fixed jaw member 120 is connected to a second electrical potentialthrough tube 160 that is connected at its proximal end to lead 310 c.More particularly, as best shown in FIGS. 2, 4, 10 and 11, fixed jaw 120is welded to the rotating tube 160 and includes a fuse clip, spring clipor other electro-mechanical connection that provides electricalcontinuity to the fixed jaw member 120 from lead 310 c. The rotatingtube 160 includes an elongated guide slot 167 disposed in an upperportion thereof that is dimensioned to carry lead 311 therealong. Lead311 carries a first electrical potential to movable jaw 110. A secondelectrical connection from lead 310 c is conducted through the tube 160to the fixed jaw member 120. Details relating to the electricalconnections are described in the aforementioned U.S. patent applicationSer. No. 10/460,926, now U.S. Pat. No. 7,156,846.

A tubular insulating boot 500 is included that is configured to mountover the pivot 103 and at least a portion of the end effector assembly100. The tubular insulating boot 500 is flexible to permit opening andclosing of the jaw members 110 and 120 about pivot 103. The flexibleinsulating boot 500 is made typically of any type of visco-elastic,elastomeric or flexible material that is biocompatible. Such avisco-elastic, elastomeric or flexible material is preferably durableand is configured to minimally impede movement of the jaw members 110and 120 from the open to the closed positions. The particularly selectedmaterial of the flexible insulating boot 500 has a dielectric strengthsufficient to withstand the voltages encountered during electrosurgery,and is suitable for use with a sterilization process that does notsubstantially impair structural integrity of the boot, such as anethylene oxide process that does not melt or otherwise impair thestructural integrity of the insulating boot 500. The insulating boot 500is dimensioned to further reduce stray electrical potentials so as toreduce the possibility of subjecting the patient tissue to unintentionalelectrosurgical RF energy.

As best shown in FIGS. 2, 3, 12, 16 and 17, one end of the tubularinsulating boot 500 is disposed on at least a portion of the exteriorsurface of shaft 12 while the other end of the tubular insulating boot500 is disposed on at least a portion of the exterior surfaces of jawmembers 110 and 120. Operability of the jaw members 110 and 120 issubstantially unimpeded and not affected significantly by the flexibleinsulating boot 500. More particularly, the tubular insulating boot 500is maintained on the shaft 12 such that boot 500 remains in asubstantially stationary position axially with respect to reciprocatingsleeve 60 and the jaw members 110 and 120. The flexible insulating boot500 expands and contracts both radially and axially to cover the pivotpin 103 and to accommodate motion of the protrusion 117 and the movablejaw member 110.

Again, as previously mentioned, since one end of the tubular insulatingboot 500 is disposed on at least a portion of the shaft 12 while theother end of the tubular insulating boot 500 is disposed on at least aportion of the exterior surfaces of fixed jaw member 120 and pivotingjaw member 110, operability of the pivoting jaw member 110 and the fixedjaw member 120, either with respect to reciprocation of thereciprocating sleeve 60 or rotation of the rotating tube 160, is notsignificantly limited by or impeded by the flexible insulating boot 500.The tubular insulating boot 500 does not interface with the shaft 12 butrather remains in a substantially stationary position axially withrespect to reciprocating sleeve 60 and the jaw members 110 and 120.

As best shown in FIGS. 1, 4 and 10, once actuated, handle 40 moves in agenerally arcuate fashion towards fixed handle 50 about the pivot pins29 a and 29 b that forces driving flange 47 proximally against the driveassembly 150 that, in turn, pulls reciprocating sleeve 60 in a generallyproximal direction to close jaw member 110 relative to jaw member 120.Moreover, proximal rotation of the handle 40 causes the locking flange44 to release, i.e., “unlock”, the trigger assembly 70 for selectiveactuation.

The operating features and relative movements of the internal workingcomponents of the forceps 10 and the trigger assembly 70 are shown byphantom representation in the various figures and explained in moredetail with respect to the aforementioned U.S. patent application Ser.No. 10/460,926, now U.S. Pat. No. 7,156,846, and also in U.S. patentapplication Ser. No. 10/970,307, now U.S. Pat. No. 7,232,440, thecontents of both of which are incorporated herein in their entirety.

As can be appreciated, as illustrated in FIG. 15, the utilization of anover-the-center pivoting mechanism will enable the user to selectivelycompress the coil spring 67 a specific distance that, in turn, imparts aspecific pulling load on the reciprocating sleeve 60 that is convertedto a rotational torque about the jaw pivot pin 103. As a result, aspecific closure force can be transmitted to the opposing jaw members110 and 120. The combination of the mechanical advantage of theover-the-center pivot along with the compressive force associated withthe compression spring 67 facilitate and assure consistent, uniform andaccurate closure pressure about tissue within a desired working pressurerange of about 3 kg/cm² to about 16 kg/cm² and, preferably, about 7kg/cm² to about 13 kg/cm². By controlling the intensity, frequency andduration of the electrosurgical energy applied to the tissue, the usercan seal tissue.

As best shown in FIGS. 4, 6-9 and 18, the knife assembly 140 includes anelongated rod 182 having a bifurcated distal end comprising prongs 182 aand 182 b that cooperate to receive a knife bar 184 therein. The knifeassembly 180 also includes a proximal end 183 that is keyed tofacilitate insertion into tube 160 of the rotating assembly 80. A knifewheel 148 is secured to the knife bar 182 by a pin 143. Moreparticularly, the elongated knife rod 182 includes apertures 181 a and181 b that are dimensioned to receive and secure the knife wheel 148 tothe knife rod 182 such that longitudinal reciprocation of the knifewheel 148, in turn, moves the elongated knife rod 182 to sever tissue420. More details relating to the operational features of the knifeassembly 180 are discussed in the previously mentioned U.S. patentapplication Ser. No. 10/460,926, which is incorporated herein byreference in its entirety.

As best shown in the exploded view of FIG. 4 and in FIGS. 14-15, theelectrical leads 310 a, 310 b, 310 c and 311 are fed through the housing20 by electrosurgical cable 310. More particularly, the electrosurgicalcable 310 is fed into the bottom of the housing 20 through fixed handle50. Lead 310 c extends directly from cable 310 into the rotatingassembly 80 and connects (via a fused clip or spring clip or the like)to tube 60 to conduct the second electrical potential to fixed jawmember 120. Leads 310 a and 310 b extend from cable 310 and connect tothe hand switch or joy-stick-like toggle switch 200. Details relating tothe switch 200 are disclosed in the aforementioned U.S. patentapplication Ser. Nos. 10/460,926 and 10/970,307, now U.S. Pat. Nos.7,156,846 and 7,232,440, respectively.

The jaw members 110 and 120 are electrically isolated from one anothersuch that electrosurgical energy can be effectively transferred throughthe tissue to form seal 450, as shown in FIGS. 18 and 19. The twoelectrical potentials are isolated from one another by virtue of theinsulative sheathing surrounding cable lead 311. At least one of the jawmembers 110 and 120 is adapted to connect to a source of electrosurgicalenergy (a generator (not shown)) such that at least one of the jawmembers 110 and 120 is capable of conducting electrosurgical energy totissue held therebetween.

In addition, by virtue of the flexible insulating boot 500 of thepresent disclosure, desired motion of and force between the jaw members110 and 120 is maintained and substantially unimpeded while at the sametime insulating boot 500 further insulates the patient tissue frompossible stray energy from the exterior surfaces of the jaw members 110and 120 and the associated elements, e.g., pivot 103 (See FIG. 2).Details relating to various forceps that may be utilized with aninsulating boot include the commonly-owned aforementioned instrumentdescribed in U.S. patent application Ser. Nos. 10/460,926 and10/970,307, now U.S. Pat. Nos. 7,156,846 and 7,232,440, respectively,and commonly-owned and concurrently filed U.S. Provisional PatentApplication Ser. No. 60/722,177 entitled “INLINE VESSEL SEALER ANDDIVIDER”, filed on Sep. 30, 2005, filed as U.S. patent application Ser.No. 11/540,335, published as U.S. Patent Application Publication No.US2007/0078456 A1, the entire contents of which is incorporated byreference herein.

As mentioned above with respect to FIG. 3, at least one jaw member,e.g., 120, may include a stop member 750 that limits the movement of thetwo opposing jaw members 110 and 120 relative to one another. The stopmember 750 extends from the sealing surface 122 a predetermined distanceaccording to the specific material properties (e.g., compressivestrength, thermal expansion, etc.) to yield a consistent and accurategap distance “G” (preferably between about 0.001 inches to about 0.006inches, i.e., between about 0.03 mm to about 0.15 mm) during sealing(FIG. 18). The non-conductive stop members 750 are sprayed or otherwisedeposited onto the jaw members 110 and 120 (e.g., overmolding, injectionmolding, etc.), stamped onto the jaw members 110 and 120 or deposited(e.g., deposition) onto the jaw members 110 and 120. For example, onetechnique involves thermally spraying a ceramic material onto thesurface of the jaw member 110 and 120 to form the stop members 750.

As best shown in FIGS. 4, 6-9, and 18-19, as energy is being selectivelytransferred to the end effector assembly 100, across the jaw members 110and 120 and through the tissue 420, a tissue seal 450 forms isolatingtwo tissue halves 420 a and 420 b. The knife assembly 140 is thenactivated via the trigger assembly 70, to progressively and selectivelydivide the tissue 420 along an ideal tissue plane in precise manner toeffectively and reliably divide the tissue 420 into two sealed halves420 a and 420 b (See FIGS. 18-19) with a tissue gap 475 therebetween.The knife assembly 140 allows the user to quickly separate the tissue420 immediately after sealing or, if desired, without sealing, withoutsubstituting a cutting instrument through a cannula or trocar port. Ascan be appreciated, accurate sealing and dividing of tissue 420 isaccomplished with the same forceps 10. Again, desired motion or movementof and force between the jaw members 110 and 120 is maintained andsubstantially unimpeded in the presence of the flexible insulating boot500 of the present disclosure. For example, FIG. 16 is a side view ofthe end effector assembly 100 having the flexible insulating boot 500 ofthe present disclosure illustrating the jaw members 110 and 120 in theopen position. FIG. 17 is a side view of the end effector assembly 100having the flexible insulating boot 500 of the present disclosureillustrating the jaw members 110 and 120 in the closed position.

FIGS. 20 and 21 show an open forceps 1000 for use with an insulatingboot 1500 of the present disclosure. Forceps 1000 includes elongatedshaft portions 1012 a and 1012 b each having a proximal end 1014 a, 1014b and a distal end 1016 a and 1016 b, respectively. The forceps 1000includes an end effector assembly 1100 that attaches to the distal ends1016 a and 1016 b of shafts 1012 a and 1012 b, respectively. The endeffector assembly 1100 includes pair of opposing jaw members 1110 and1120 that are pivotably connected about a pivot pin 1065 and that aremovable relative to one another to grasp vessels and/or tissue.

Each shaft 1012 a and 1012 b includes a handle 1015 and 1017,respectively, disposed at the proximal end 1014 a and 1014 b thereofthat each define a finger hole 1015 a and 1017 b, respectively,therethrough for receiving a finger of the user. Finger holes 1015 a and1017 b facilitate movement of the shafts 1012 a and 1012 b relative toone another that, in turn, pivot the jaw members 1110 and 1120 from anopen position wherein the jaw members 1110 and 1120 are disposed inspaced relation relative to one another to a clamping or closed positionwherein the jaw members 1110 and 1120 cooperate to grasp tissue orvessels therebetween.

Shaft 1012 a is secured about pivot 1065 and positioned within a cut-outor relief 1021 such that shaft 1012 a is movable relative to shaft 1012b. More particularly, when the user moves the shaft 1012 a relative toshaft 1012 b to close or open the jaw members 1110 and 1120, the distalportion of shaft 1012 a moves within cutout 1021. One of the shafts,e.g., 1012 b, includes a proximal shaft connector 1077 that is designedto connect the forceps 1000 to a source of electrosurgical energy suchas an electrosurgical generator (not shown).

The distal end of the cable 1070 connects to a handswitch 1050 to permitthe user to selectively apply electrosurgical energy as needed to sealtissue or vessels grasped between jaw members 1110 and 1120 (See FIGS.20, 21 and 25). As best shown in FIGS. 22-23, jaw members 1110 and 1120include outer insulative coatings or layers 1116 and 1126 that aredimensioned to surround the outer periphery of jaw member 1110 and 1120and expose electrically conductive sealing surfaces 1112 and 1122,respectively on an inner facing surface thereof. The electricallyconducive sealing surfaces 1112 and 1122 conduct electrosurgical energyto the tissue upon activation of the handswitch 1050 such that the twoopposing electrically conductive sealing surfaces 1112 and 1122 conductbipolar energy to seal tissue disposed between the sealing surfaces 1112and 1122 upon activation. At least one of the jaw members 1110 and 1120is adapted to connect to the source of electrosurgical energy (notshown) such that at least one of the jaw members 1110 and 1120 iscapable of conducting electrosurgical energy to tissue heldtherebetween.

As best shown in FIG. 24, the upper jaw member 1110 includes an exteriorsurface or outer edge 1210 extending from a distal end or tip 1215 ofthe upper jaw member 1110. Similarly, the lower jaw member 1120 includesan exterior surface or outer edge 1220 extending from a distal end ortip 1225 of the lower jaw member 1120. In addition, in accordance withthe present disclosure, generally tubular insulating boot 1500 having alength “L” may be positioned about at least a portion of the endeffector assembly 1100. The distal end 1504 of the insulating boot 1500is disposed on the outer edge 1210 of the upper jaw member 1110 at adistance “d” retracted away from the tip 1215 and at a correspondingposition on the outer edge 1220 of the lower jaw member 1120 retractedaway from the tip 1225.

In one embodiment, the length “L” of the insulating boot 1500 is suchthat the proximal end 1502 of the insulating boot 1500 is disposed onthe outer edges 1210 and 1220 so that the pivot pin 1065 remainsexposed. In an alternate embodiment shown in phantom in FIG. 24, thelength “L” of the insulating boot 1500 is such that the proximal end1502 of the insulating boot 1500 is disposed on the outer edges 1210 and1220 so that the pivot pin 1065 is covered by the insulating boot 1500.Those skilled in the art recognize that the distance “d” and the length“L” of the insulating boot 1500 are chosen so as to maximize continuedoperability of the jaw members 1110 and 1120 to perform their intendedfunctions.

In either embodiment, the insulating boot 1500 limits stray currentdissipation to surrounding tissue upon activation and continued use ofthe forceps 1000. As mentioned above, the insulating boot 1500 is madefrom any type of visco-elastic, elastomeric or flexible material that isbiocompatible and that is configured to minimally impede movement of thejaw members 1110 and 1120 from the open to closed positions. Moreover,in one embodiment, the material is selected to have a dielectricstrength sufficient to withstand the voltages encountered duringelectrosurgery, and is suitable for use with a sterilization processthat does not substantially impair structural integrity of the boot,such as an ethylene oxide process. More particularly, the insulatingboot 1500 further reduces stray electrical potential so as to reduce thepossibility of subjecting the patient tissue to unintentionalelectrosurgical RF energy.

As best shown in FIG. 24, the tubular insulating boot 1500 is disposedon at least a portion of the exterior surface 1210 of jaw members 1110and 1120 such that operability of the jaw members 1110 and 1120 issubstantially unimpeded and not affected significantly by the flexibleinsulating boot 1500. More particularly, the tubular insulating boot1500 remains in a substantially stationary position axially with respectto the jaw members 1110 and 1120, i.e., the distance “d” remainssubstantially constant during motion of the upper jaw member 1110 withrespect to the lower jaw member 1120. However, the flexible insulatingboot 1500 expands and contracts both radially and axially to accommodatemotion of the movable jaw member 1110, and to cover the pivot pin 1103where applicable.

Details relating to the jaw members 1110 and 1120 and various elementsassociated therewith are discussed in commonly-owned U.S. applicationSer. No. 10/962,116, filed on Oct. 8, 2004, and entitled “Open VesselSealing Instrument with Hourglass Cutting Mechanism and Over-RatchetSafety”, the entire contents of which are hereby incorporated byreference herein.

As best illustrated in FIG. 23, jaw member 1120 (or jaw member 1110)includes one or more stop members 1175 disposed on the inner facingsurface of the electrically conductive sealing surface 1122. The stopmembers are designed to facilitate gripping and manipulation of tissueand to define a gap “G” between opposing sealing surfaces 1112 and 1122during sealing (See FIGS. 24 and 25). The separation distance duringsealing or the gap distance “G” is within the range of about 0.001inches (about 0.03 millimeters) to about 0.006 inches (about 0.016millimeters) for optimizing the vessel sealing process.

As best seen in FIGS. 22 and 23, the jaw members 1110 and 1120 include aknife channel 1115 disposed therebetween that is configured to allowdistal translation of a cutting mechanism (not shown) therewithin tosever tissue disposed between the seal surfaces 1112 and 1122. Thecomplete knife channel 1115 is formed when two opposing channel halves1115 a and 1115 b associated with respective jaw members 1110 and 1120come together upon grasping of the tissue. Details relating to thecutting mechanism and associated actuating mechanism (not shown) arediscussed in commonly-owned U.S. application Ser. No. 10/962,116, theentire contents of which are hereby incorporated by reference herein.

FIG. 21 shows the details of a ratchet 1030 for selectively locking thejaw members 1110 and 1120 relative to one another during pivoting. Afirst ratchet interface 1031 a extends from the proximal end 1014 a ofshaft member 1012 a towards a second ratchet interface 1031 b on theproximal end 1014 b of shaft 1012 b in general vertical registrationtherewith such that the inner facing surfaces of each ratchet 1031 a and1031 b abut one another upon closure of the jaw members 1110 and 1120about the tissue 400. The position associated with the cooperatingratchet interfaces 1031 a and 1031 b holds a specific, i.e., constant,strain energy in the shaft members 1012 a and 1012 b that, in turn,transmits a specific closing force to the jaw members 1110 and 1120within a specified working range of about 3 kg/cm² to about 16 kg/cm²when the jaw members 1110 and 1120 are ratcheted.

In operation, the surgeon utilizes the two opposing handle members 1015and 1017 to grasp tissue between jaw members 1110 and 1120. The surgeonthen activates the handswitch 1050 to provide electrosurgical energy toeach jaw member 1110 and 1120 to communicate energy through the tissueheld therebetween to effect a tissue seal. Once sealed, the surgeonactivates the actuating mechanism to advance the cutting blade throughthe tissue to sever the tissue 400 along the tissue seal.

The jaw members 1110 and 1120 are electrically isolated from one anothersuch that electrosurgical energy can be effectively transferred throughthe tissue to form a tissue seal. Each jaw member, e.g., 1110, includesa uniquely-designed electrosurgical cable path disposed therethroughthat transmits electrosurgical energy to the electrically conductivesealing surface 1112. The two electrical potentials are isolated fromone another by virtue of the insulative sheathing surrounding each cablelead 1071 a, 1071 b and 1071 c. In addition, to further enhance safety,as noted previously, insulating boot 1500 may be positioned about atleast a portion of the end effector assembly 1000, and optionally thepivot 1065, to limit stray current dissipation to surrounding tissueupon activation and continued use of the forceps 1010. As mentionedabove, the insulating boot 1500 is made from any type of visco-elastic,elastomeric or flexible material that is biocompatible and that isconfigured to minimally impede movement of the jaw members 1110 and 1120from the open to closed positions.

The presently disclosed insulating boot may also be utilized with aforceps 2010 designed for both bipolar electrosurgical treatment oftissue (either by vessel sealing as described above or coagulation orcauterization with other similar instruments) and monopolar treatment oftissue. For example, FIGS. 26-32 show one embodiment of a forceps 2010that includes a monopolar element, e.g., element 2154 that may beselectively extended and selectively activated to treat tissue. FIGS.33A-33B show alternate embodiments of the present disclosure that showthat the knife 2185 may be extended from the distal end of the endeffector assembly 2100 and selectively energized to treat tissue in amonopolar fashion. FIG. 34A shows another embodiment of a forceps 2010′wherein the bottom jaw member 2120′ extends distally from the top jawmember 2110′ to allow the surgeon to selectively energize the bottom jawmember 2120′ and treat tissue in a monopolar fashion. FIG. 34B shows yetanother embodiment of a forceps 2010″ wherein the jaw members 2110″ and2120″ include tapered distal ends that are selectively energized with asingle electrical potential to treat tissue in a monopolar fashion.FIGS. 35A-38B show other configurations of the end effector assemblyand/or bottom or second jaw member that are configured to suit aparticular purpose or to achieve a desired surgical result. Aninsulating boot 2500 may be configured to cover the various uninsulatedelements of the end effector assembly 1100 of the above mentioned andbelow further described elements including but not limited to portionsof one or both of the jaw members 2110 and 2120, the pivot 2103 and theknife assembly 2180 etc. The insulating boot 2500 is contemplated to beparticularly useful with forceps capable of monopolar activation sincethe boot prevents the various uninsulated elements from acting asalternative or unintended current sources or paths during activationthat may result in unintended or undesirable tissue effects during aparticular surgical procedure.

More particularly, FIGS. 26-31 show one embodiment wherein a monopolarelement 2154 is housed for selective extension within one jaw member,e.g., jaw member 2120, of the end effector assembly 2100. Monopolarelement 2154 is designed to move independently from knife assembly 2180and may be extended by further proximal movement of the trigger assembly2070 (FIGS. 26, 30 and 31) or by a separate actuator 2450 (FIG. 32).

The monopolar element 2154 may be connected to a reciprocating rod 2065that extends through an elongated notch 2013 in the outer periphery ofthe shaft 2012 as best seen in FIG. 27. Drive rod 2060 that actuates theknife 2185 extends through the inner periphery of shaft 2012. In orderto extend the monopolar element 2154, the jaw members 2110 and 2120 areinitially closed and the knife 2185 is advanced distally utilizing thetrigger assembly 2070 (See FIG. 30). As best shown in FIG. 28, thetrigger 2071 is initially advanced to translate the knife 2185 distallyto cut through tissue, i.e., the “cut” stage (shown in phantom).Thereafter and as shown in FIGS. 28 and 31, the trigger 2071 may befurther actuated in a proximal direction to extend the monopolar element2154, i.e., the “extend” stage (shown in phantom).

As best shown in FIG. 29, a tubular insulating boot 2500 is includedthat is configured to mount over the pivot 2103, connecting the upper,pivoting jaw member 2110 with the lower, fixed jaw member 2120, and overat least a portion of the end effector assembly 2100. The tubularinsulating boot 2500 is flexible to permit opening and closing of thejaw members 2110 and 2120 about the pivot 2103. The flexible insulatingboot 2500 is made typically of any type of visco-elastic, elastomeric orflexible material that is biocompatible. More particularly, theinsulating boot 2500 is configured to reduce stray electrical potentialso as to reduce the possibility of subjecting the patient tissue tounintentional electrosurgical RF energy.

As best shown in FIG. 29, one end of the tubular insulating boot 2500 isdisposed on at least a portion of the exterior surface of shaft 2012while the other end of the tubular insulating boot 2500 is disposed onat least a portion of the exterior surfaces of fixed jaw member 2120 andpivoting jaw member 2110 such that operability of the jaw members 2110and 2120 is substantially unimpeded and not affected significantly bythe flexible insulating boot 2500. More particularly, the tubularinsulating boot 2500 is maintained on the shaft 2012 such that boot 2500remains in a substantially stationary position axially with respect toreciprocating sleeve 2060 and the jaw members 2110 and 2120. Theflexible insulating boot 2500 expands and contracts both radially andaxially to cover the pivot pin 2103 and to accommodate motion ofprotrusion 2117 and the movable jaw member 2110.

Details relating to this particular embodiment of a monopolar forceps isdisclosed in aforementioned commonly-owned U.S. application Ser. No.10/970,307, the entire contents of which are hereby incorporated byreference herein.

FIG. 32 shows another embodiment of the present disclosure wherein themonopolar element 2154 is selectively extendible utilizing a secondactuator 2450. As described above, the knife 2185 is advanced byactuating the trigger 2071 in a generally proximal direction. Themonopolar element 2154 is selectively advanceable independently of theknife 2185 and may be extended when the jaw members 2110 and 2120 aredisposed in either the open configuration or closed configuration. Theactuator 2450 may be electrically configured to activate the monopolarelement 2154 automatically once extended or manually by activationswitch 2200 or perhaps another switch (not shown). As mentioned above, asafety circuit 2460 may be employed to deactivate jaw members 2110 and2120 when the monopolar element 2154 is extended such that activation ofthe switch 2200 energizes the monopolar element 2154. In the case of aseparate activation switch for the monopolar element, the safety circuitwould deactivate the switch 2200.

In a similar manner as discussed previously with respect to FIG. 29, andas shown in FIG. 32, the tubular insulating boot 2500 is included thatis configured to mount over the pivot 2103 and at least a portion of theend effector assembly 2100. The tubular insulating boot 2500 is flexibleto permit opening and closing of the jaw members 2110 and 2120 aboutpivot 2103.

Those skilled in the art recognize that the material properties of theinsulating boot 2500 and operability considerations from disposition ofthe insulating boot 2500 are in all respects either similar to or insome cases identical to those described in the preceding discussion withrespect to FIGS. 26-31.

FIGS. 33A-33C show another alternate embodiment of the presentdisclosure of a forceps 2200 wherein the knife 2185 can be extendeddistally beyond the jaw members 2210 and 2220, respectively, andseparately energized to treat tissue. In this instance, when the knifeis extended beyond the jaw members 2210 and 2220, respectively, theknife 2185 becomes the monopolar element.

As illustrated in FIGS. 33A-33C and partially in FIG. 34B, once theknife 2185 extends beyond the jaw members 2110 and 2120, a safety orswitch deactivates energizing circuitry to the jaw members 2110 and 2120and activates the energizing circuitry to the knife 285 such thatactivation of the switch 2200 energizes the knife 2185 and the jawmembers remain neutral. For example, the stop 2119 may act as a safetyswitch such that upon being forced by the knife 2185 out of or away fromthe knife channel 2115, the stop 2119 deactivates circuitry to the jawmembers 2210 and 2220 and activates circuitry to the monopolar knife2185 and the return electrode 2550. A separate lead 2069 may be used toelectrically communicate with the generator 2300 (See FIG. 34B). As canbe appreciated, the knife 2185 may now be used in a monopolar fashion totreat tissue.

Upon release of a trigger such as trigger 2070 (See FIG. 26), the knife2185 automatically retracts into the knife channel 2115 and back to thepre-actuated position as shown in FIG. 33A. At the same time, the stop2119 reverts to its original position to temporarily block the knifechannel 2115 for subsequent actuation.

Again, in a similar manner as discussed previously with respect to FIG.29, the tubular insulating boot 2500 is included that is configured tomount over the pivot 2103 and at least a portion of the end effectorassembly 2200. The tubular insulating boot 2500 is flexible to permitopening and closing of the jaw members 2210 and 2220 about pivot 2103.

Again, those skilled in the art recognize that the material propertiesof the insulating boot 2500 and operability considerations fromdisposition of the insulating boot 2500 are similar to those describedin the preceding discussions.

As shown in FIG. 34A and partially in the schematic FIG. 34B, anotherembodiment of a forceps 2010′ according to the present disclosurewherein the lower jaw member 2120′ is designed to extend beyond thedistal end of jaw member 2110′. In order to switch from a bipolar modeof the operation to a monopolar mode, the surgeon activates a switch orcontrol that energizes jaw member 2120′ to a first potential andactivates a return pad 2550 to a second potential. Energy is transferredfrom jaw member 2120, through tissue, and to the return pad 2550 totreat tissue. The distal end of jaw member 2120′ acts as the monopolarelement for treating the tissue and may be shaped accordingly to enhanceelectrosurgical effect.

FIG. 34B shows yet another schematic embodiment of a forceps 2010″according to the present disclosure wherein the distal ends of both jawmembers 2110″ and 2120″ are shaped to treat tissue when disposed in amonopolar mode. More particularly, the distal tips 2112 a″ and 2122 a″are preferably elongated or tapered to enhance energy delivery when theforceps 2010″ is disposed in the monopolar mode. When disposed in thebipolar mode, the tapered ends 2112 a″ and 2122 a″ do not effecttreating tissue between electrically conductive plates 2112″ and 2122″.

A control switch 2505 is preferably included that regulates thetransition between bipolar mode and monopolar mode. Control switch 2505is connected to generator 2300 via cables 2360 and 2370. A series ofleads 2510, 2520 and 2530 are connected to the jaw members 2110″, 2120″and the return electrode 2550, respectively. As best shown in the tabledepicted in FIG. 34B, each lead 2510, 220, and 2530 is provided with anelectrical potential or remains neutral depending upon the particular“mode” of the forceps 2010″. For example, in the bipolar mode, lead 2510(and, in turn, jaw member 2110″) is energized with a first electricalpotential and lead 2520 (and, in turn, jaw member 2120″) is energizedwith second electrical potential. As a result thereof, electrosurgicalenergy is transferred from jaw member 2110″ through the tissue and tojaw member 2120″. The return electrode 2550 remains off or neutral.

In a monopolar mode, jaw member 2110″ and 2120″ are both energized withthe same electrical potential and the return pad 2550 is energized witha second electrical potential forcing the electrical current to travelfrom the jaw members 2110″ and 2120″, through the tissue and to thereturn electrode 2550. This enables the jaw members 2110″ and 2120″ totreat tissue in a monopolar fashion that, as mentioned above,advantageously treats a vascular tissue structures and/or allows quickdissection of narrow tissue planes. As can be appreciated, all of theleads 2510, 2520 and 2530 may be deactivated when the forceps 2010″ isturned off or idle.

Yet again, as discussed previously with respect to FIG. 29, the tubularinsulating boot 2500 is included that is configured to mount over thepivot 2103 and at least a portion of the end effector assembly 2100′.

FIGS. 35A and 35B show an alternate embodiment of the forceps 2010according to the present disclosure that includes a second or bottom jawmember 2520′ that is manufactured such that the distal end 2522 a of thetissue sealing surface 2522 extends beyond the bottom jaw housing 2524.More particularly, in this particular embodiment, the tissue sealingsurface 2522 is made from a stamped sheet metal that is formed atop astamped sheet metal skeleton 2532. The proximal end of the sheet metalskeleton 2532 may be configured with various pivot points (or apertures2534), cam slots or grooves depending upon the particular type of pivotaction associated with the forceps 2010. As can be appreciated, thesealing surface 2522 may be supported atop a hem or spine 2535 thatextends along the skeleton 2532 by many ways known in the art.

An insulating layer 2540 is disposed between the skeleton 2532 and thetissue sealing surface 2522 to isolate the electrically conductivesealing surface 2522′ from hem 2535 during activation. The stampedtissue sealing surface 2522′ is formed of a double layer of sheet metalmaterial separated by a slot or knife channel 2515 that allows selectivereciprocation of a knife, such as knife 2185 disclosed in FIGS. 33A-33C,therein. The distal end 2522 a of the tissue sealing surface 2522 may bebent 180° to provide a larger conductive surface area that extendsbeyond the jaw housing 2524.

It is envisioned that the tissue sealing surface 2522 may be curved orstraight depending upon a particular surgical purpose. The jaw housing2524 may be overmolded to encapsulate the hem 2535 of the skeleton 2532and sealing plate 2522 that serves to insulate surrounding tissue fromthe conductive surfaces of the sealing plate 2522 as well as to give thejaw member 2520′ a desired shape at assembly.

In a similar manner as discussed previously with respect to FIG. 29, andas shown in FIG. 32, the tubular insulating boot 2500 is included ofwhich one end is configured to mount over the sheet metal skeleton 2532and pivot pin aperture 2534 and another end of the insulating boot 2500configured to mount over at least a portion of an exterior surface ofreciprocating sleeve 2060. The tubular insulating boot 2500 is flexibleto permit opening and closing of the jaw members 2110 and 2520′ aboutpivot 2103.

Details relating to the forceps 2010′, which is manufactured such thatthe distal end 2522 a′ of the tissue sealing surface 2522 extends beyondthe bottom jaw housing 2524, are disclosed in previously mentionedcommonly owned U.S. patent application Ser. No. 10/970,307 that isincorporated by reference herein.

FIGS. 36A and 36B show another embodiment of the bottom or second jawmember 2620 that includes both an electrically conductive sealingsurface 2622 for sealing purposes as well as an electrically conductivesurface 2632 that is designed for monopolar activation. Moreparticularly, the bottom jaw member 2620 includes a jaw housing 2624that supports (or encapsulates) a tissue sealing surface 2622. A knifechannel 2615 is disposed along the length of the tissue sealing surface2622 and allows reciprocation of a knife therein. An insulating layer2634 is positioned at or proximal to the distal end of the tissuesealing surface 2622 distal to the knife channel 2615. A secondconductive material 2632 (that may or may not be the same material astissue sealing surface 2622) is disposed on the opposite side of theinsulating layer 2634.

It is envisioned that the insulating material 2634 will isolate themonopolar portion 2632 during electrical activation of tissue surface2622 and isolate the tissue surface 2622 during electrical activation ofmonopolar element 2632. As can be appreciated, the two differentelectrically conductive elements 2622 and 2632 are connected toelectrical generator 2300 by different electrical connections and may beselectively activated by the user. Various switches or electricalcontrol elements or the like (not shown) may be employed to accomplishthis purpose.

Still yet again, to further enhance safety, as discussed previously withrespect to FIG. 29, the tubular insulating boot 2500 is included that isconfigured to mount over the pivot (not shown) and at least a portion ofthe end effector assembly. The tubular insulating boot 2500 is flexibleto permit opening and closing of the jaw members 2110 and 2620.

Bottom or second jaw member 2620 includes both an electricallyconductive sealing surface 2622 for sealing purposes as well as anelectrically conductive surface 2632 that is designed for monopolaractivation are disclosed in previously mentioned commonly owned U.S.patent application Ser. No. 10/970,307 which is incorporated byreference herein.

FIGS. 37A and 37B show another embodiment of an end effector assembly2700 according to the present disclosure that includes top and bottomjaw members 2710 and 2720, respectively each including similar jawelements as described above, i.e., tissue sealing surfaces 2712 and2722, respectively and insulative housings 2714 and 2724, respectively.In a similar manner as mentioned above with respect to tissue sealingsurface 2622 and knife channel 2615, the tissue sealing surfaces 2712and 2722 of jaw members 2710 and 2720 mutually cooperate to form a knifechannel 2715 that allows knife 2185 to be selectively reciprocatedtherethrough. More particularly, jaw member 2710 includes a first partof knife channel 2715 a and jaw member 2720 includes a second part ofthe knife channel 2715 b that align to form knife channel 2715.

As best shown in FIG. 37B, knife channels 2715 a and 2715 b are alignedin vertical registration along one side of the jaw members 2710 and 2720to allow reciprocation of knife 2185 therethrough. Knife channel 2715 bof jaw member 2720 is wider (i.e., as measured transversally across thelength of the jaw member 2720) and includes a separate channel 2715 b 1that is dimensioned to slidingly receive a monopolar element 2754therethrough. A trigger 70 (or the like) may be utilized as describedabove with respect to FIGS. 26-31 to extend the monopolar element 2754for treatment of tissue. In addition, the monopolar element 2754 and theknife 2185 may be made of separate components, as shown, or themonopolar element 2754 and the knife 2185 may be integral with oneanother.

As can be appreciated various switching algorithms may be employed toactivate both the bipolar mode for vessel sealing and the monopolar modefor additional tissue treatments (e.g., dissection). Also, a safety orlockout may be employed either electrically, mechanically orelectromechanically to “lock out” one electrical mode during activationof the other electrical mode. In addition, a toggle switch (or the like)may be employed to activate one mode at a time for safety reasons. Themonopolar element 2754 may also include a safety (either mechanical,electrical or electro-mechanical—not shown) that only allows electricalactivation of the monopolar element 2754 when the monopolar element 2754is extended from the distal end of jaw member 2720. Insulating boot 2500is included that is configured to mount over the pivot 2103 and at leasta portion of the end effector assembly 2100.

FIGS. 38A and 38B show yet another embodiment of bottom jaw member 2820that may be utilized for both bipolar vessel sealing and monopolartissue dissection or other monopolar tissue treatments. Moreparticularly, jaw member 2820 includes an outer jaw housing 2824 that isovermolded to encapsulate a tissue sealing plate 2822 therein. Tissuesealing plate 2822 includes a knife channel 2815 for reciprocating aknife as described in detail above. Tissue sealing plate 2822 alsoincludes a sealing surface 2822 a that is disposed in opposing relationto a corresponding sealing surface (not shown) on the opposite upper jawmember (not shown).

Tissue sealing surface 2822 also includes a sealing surface extension2822 b that extends through a distal end 824 a of the overmolded jawhousing 2824. As can be appreciated, sealing surface extension 2822 b isdesigned for monopolar tissue dissection, enterotomies or other surgicalfunctions and may be separately electrically energized by the user by ahand switch, footswitch or at the generator 2300 in a similar manner asdescribed above (See FIG. 34B). As can be appreciated, the extension2822 b also serves to further anchor the sealing plate 2822 in the jawhousing 2824 during the overmolding process. Insulating boot 2500 isincluded that is configured to mount over the pivot 2103 and at least aportion of the end effector assembly.

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the same. For example and although the general operating componentsand inter-cooperating relationships among these components have beengenerally described with respect to a vessel sealing forceps, otherinstruments may also be utilized that can be configured to allow asurgeon to selectively treat tissue in both a bipolar and monopolarfashion. Such instruments include, for example, bipolar grasping andcoagulating instruments, cauterizing instruments, bipolar scissors, etc.

Furthermore, those skilled in the art recognize that while theinsulating boots 500, 1500, or 2500 are disclosed as having a generallytubular configuration, the cross-section of the generally tubularconfiguration can assume substantially any shape such as, but notlimited to, an oval, a circle, a square, or a rectangle, and alsoinclude irregular shapes necessary to cover at least a portion of thejaw members and the associated elements such as the pivot pins and jawprotrusions, etc.

In addition, while several of the disclosed embodiments show endoscopicforceps that are designed to close in a unilateral fashion, forceps thatclose in a bilateral fashion may also be utilized with the insulatingboot described herein. The presently disclosed insulating boot may beconfigured to fit atop or encapsulate pivot or hinge members of otherknown devices such as jawed monopolar devices, standard laparoscopic“Maryland” dissectors and/or bipolar scissors.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of preferred embodiments. Those skilled in the art willenvision other modifications within the scope and spirit of the claimsappended hereto.

1. An electrosurgical forceps, comprising: a shaft having a pair of jawmembers at a distal end thereof, the jaw members being movable about apivot from a first position wherein the jaw members are disposed inspaced relation relative to one another to a second position wherein thejaw members are closer to one another for grasping tissue, the shaftdefining a longitudinal axis therethrough; a movable handle thatactuates a drive assembly to move the jaw members relative to oneanother; at least one of the jaw members including a tissue-engagingsurface adapted to connect to a source of electrical energy such thatthe at least one jaw member is capable of conducting energy to tissueheld therebetween; and a flexible insulating boot mounted over thepivot, the flexible insulating boot having a proximal portion disposedon a portion of the shaft and a distal portion disposed on a portion ofan exterior surface of the pair of jaw members proximal to thetissue-engaging surface of the at least one jaw member, the proximalportion and the distal portion of the flexible insulating boot disposedsuch that the flexible insulating boot remains in a substantiallystationary position relative to the longitudinal axis and with respectto a reciprocating sleeve of the drive assembly and the jaw members whenthe drive assembly mechanically advances the reciprocating sleeve toapply a predetermined closure force between the jaw members.
 2. Anelectrosurgical forceps according to claim 1, wherein at least one ofthe jaw members includes a series of stop members disposed thereon forregulating distance between the jaw members such that a gap is createdbetween the jaw members during the sealing process.
 3. Anelectrosurgical forceps according to claim 1, wherein the forcepsincludes a knife that is selectively deployable to cut tissue disposedbetween the jaw members.
 4. An electrosurgical forceps according toclaim 1, wherein the insulating boot is made of at least one of aviscoelastic, elastomeric, and flexible material suitable for use with asterilization process that does not substantially impair structuralintegrity of the boot.
 5. An electrosurgical forceps according to claim4, wherein the sterilization process includes ethylene oxide.
 6. Anelectrosurgical forceps according to claim 1, wherein the flexibleinsulating boot has a generally tubular configuration.
 7. Anelectrosurgical forceps according to claim 1, wherein two jaw membersare adapted to connect to the source of electrical energy such that thejaw members are capable of treating tissue in a bipolar manner uponselective activation of the forceps.
 8. An electrosurgical forcepsaccording to claim 1, wherein at least one jaw member is adapted toconnect to the source of electrical energy such that the at least onejaw members is capable of treating tissue in a monopolar manner uponselective actuation of the forceps.